I now have the iSonic 110 and I am starting to get well into slalom again.

As I have mainly been freestyling and wavesailing the fifteen last years I know lots about such equipment, but not so much about slalom equipment.

Having several fins for a slalom board, how much bigger makes a difference in lift, earlier planing and going through lulls? Lets say I have a z-fins 38 for my iSonic 110. If I want a bigger fin as well how much bigger must it be to make a difference? Is a 40cm bigger or will I have to go to 42 or 44?

38 is tiny for the 110 !! I am using 44cm Z-Fin with 7.0/7.8 and 46cm with 8.6m ...

A bigger fin definitely gives you more lift, earlier planing and more drive through the lulls; it helps to power the board up and get it railing and a bigger fin is much easier to pump against in light winds.

I have the z-fin 38cm that I use with my 7.0. I also have a MFC 42 that I use with my 8.2.

The 38 is very good with the 7.0. I am thinking about getting more z-fins as I believe it is not just the size of the z-fin that makes it feel good, but the fin. Reason for my question is that I am not sure which size to get next. How big is a difference?

I know Taty Frans says the 40 cm is the best for the 2013 110. I am the same weight as him, but I am not sure I sail with the same omit of power.

I have ordered a Zfin slalom 41 S-. I have also ordered a new full on 7.8 race sail (2013 Simmer SCR) and will probably sell my freerace/streetrace 8.2 and 7.0 sails. I remember you told me before that I can get lots of use with my weight (72kg) and a 7.8 on the 110 and now with Zfins 38 and 41 I think I will be nicely covered. Guess I will use the 41 the most and the 38 when I will try to set a new personal GPS record on the board.